While the Obama administration is encouraging uninsured Americans to enroll in health coverage on the new online insurance marketplaces, federal officials are planning a campaign to persuade millions of seniors to please stay away — don't call and don't sign up. "We want to reassure Medicare beneficiaries that they are already covered, their benefits are not changing and the marketplace doesn't require them to do anything," said Michele Patrick, Medicare's deputy director for communications. To reinforce the message, the 2014 Medicare & You handbook — the 100-plus-page guide that will be sent to 52 million Medicare beneficiaries next month.